Washing device for a blanket cylinder of an offset printing press

ABSTRACT

An offset printing press having a blanket cylinder includes a washing device adjustable with respect to the blanket cylinder and comprising a rotary washing roller having a soft covering and being in frictional driving engagement with and traversible relative to the blanket cylinder, means for wetting the washing roller with wash solution, a collecting vessel underlying the washing roller, a doctor roller having a firm surface located in continuous frictional engagement with the washing roller, a doctor blade abutting the firm surface of the doctor roller for guiding therefrom into the collecting vessel ink washed off the blanket cylinder with the wash solution, and a distributor roller having a firm surface engaging the soft covering of the washing roller at a location behind the doctor roller in the rotary direction of the washing roller, the distributor roller being wettable with fresh wash solution.

United States Patent Junghans 1 1 Aug. 5, 1975 [54] WASHING DEVICE FOR ABLANKET 2,731,916 1/1956 Koch 101/425 CYLINDER OF AN 3,207,373 9/1965Darmenmann v 1 1 1 1 222/517 X PRESS 3,656,200 4/1972 Riley l5/256.523,693,547 9/1972 Morgan 1. 101/425 [75] Inventor: gudi Junghans,Wilhelmsfeld, FOREIGN PATENTS OR APPLICATIONS ermany 1,169,668 11/1969United Kingdom 101/425 [73] Assignee: Heidelberger Druckmaschinen548,280 4/1932 Germany .1 101/167 Aktiengesellschaft, Heidelberg, Germny Primary ExaminerClyde l. Coughenour [22] Filed: May 17, 1974Attorney, Agent, or FirmHerbert L. Lerner 1 1 pp bio-1470346 57 ABSTRACTRelated U,S A li ation D ta An offset printing press having a blanketcylinder in- [63] continuation of Serv 308341 21, I972 cludes a washingdevice adjustable with respect to the abandoned blanket cylinder andcomprising a rotary washing roller having a soft covering and being infrictional driv- 301 Foreign A li ti p i m ing engagement with andtraversible relative to the Nov. 24' [971 Germany 2158185 blanketcylinder, means for wetting the washing roller with wash solution, acollecting vessel underlying the 52 us. c1. 101/425; 151256.52; 222/517;washingfmle having a firm surface 222/556 located 1n continuousfrictional engagement with the 51 Int. Cl. B411 35/06; B411 41/06 washmga blade abuting [58] Field of Search U 01/425; 222/517, 556; face of thedoctor roller for guiding therefrom into the 15/2565 256-52 collectingvessel ink washed off the blanket cylinder with the wash solution, and adistributor roller having [56] Reerences Cited :1 firmnsurfacelengagingbthltle soft covering of the washing ro er at a ocation e indthe doctor roller in the UNITED STATES PATENTS rotary direction of thewashing roller, the distributor 511,934 1/1894 Cottrell 101/425 tonerbeing wettable with f h wash Solution 951,489 3/1910 Saxton 101/4252,659.305 11 /1953 Giori 101/423 x 9 Claims, 5 Drawing Figures SHEETPATENTED AUG 5 I975 FIG.

PATENTED AUG 5 I975 SHEET SHEE? PATENTED AUG 5 8975 FIG.

SHEET PATENTED AUB 5 FIG. 4

FIGS

WASHING DEVICE FOR A BLANKET CYLINDER OF AN OFFSET PRINTING PRESS Thisis a continuation, of application Ser. No. 308,341, filed Nov. 21, 1972,now abandoned.

The invention relates to a washing device adjustable with respect to theblanket cylinder in an offset printing press and, more particularly, tosuch a washing device which comprises a rotary washing roller having asoft covering and being in frictional driving engagement with andtraversible relative to the blanket cylinder, means for wetting thewashing roller with wash solution, a collecting vessel underlying thewashing roller, a doctor roller having a firm surface located incontinuous frictional engagement with the washing roller and a doctorblade abutting the firm surface of the doctor roller for guidingtherefrom into the collecting vessel ink washed off the blanket cylinderwith the wash solution. Such a washing device is The subject of and hasbeen described in my application Ser. No. 123,946 filed Mar. 15, 1971,now abandoned.

It is an object of the invention to provide a washing device for theblanket cylinder of an offset printing press which will clean theblanket cylinder of any ink thereon in the shortest possible time withthe most economical consumption of wash solution.

It is a further object of the invention to provide such a washing devicewith an improved and relatively simpler control for the supply of washsolution and an optimal distribution of the supplied wash solution Withthe foregoing and other objects in view, the washing device of theinvention is provided with a distributor roller having a firm surfaceengaging the soft covering of the washing roller at a location behindthe doctor roller in the rotary direction of the washing roller, thedistributor roller being wettable with fresh wash solution.

The nip or contact gap between the distributor roller and the washingroller effect a completely uniform distribution of the wash solutiondripping from the nozzles onto the distributor roller, so that thewashing roller is provided over the entire breadth thereof with a filmof wash solution. A further advantage of the distributor roller is thatit flings any excessively applied wash solution into the collectingvessel. This thereby effectively prevents penetration of wash solutioninto the channel of the blanket cylinder.

To effect trouble-free control of the supply of wash solution there isprovided, in accordance with a further feature of the invention, a driptube mounted above the distributor roller and extending alongsubstantially the entire length thereof, and sealing means for closingthe openings in nozzles extending from the drip tube. The sealing meansare formed, for example of small vulca nized rubber plates. They permitexact closure of the nozzle openings when only slightly compressed.

In accordance with an additional feature of the invention the washingdevice includes a control or shifter rod revolvable about an axis thatextends parallel to the drip tube, leaf spring means secured to theshifter rod and having a free end, the sealing means being carried bythe leaf spring means at the free end thereof, the shifter rod beingadjustable about the axis to two suc' cessive indexing positions whereinthe sealing means closes the nozzle openings and to a third indexingposition wherein the nozzle openings are kept open.

Although the invention is illustrated and described herein as embodiedin washing device for a blanketcylinder of an offset printing press, itis nevertheless not intended to be limited to the details shown sincevarious modifications and structural changes may be made therein withoutdeparting from the spirit of the invention and within the scope andrange of equivalents of the claims.

FIG. I is a vertical sectional view ofa washing device for a blanketcylinder of an offset printing press according to the invention, whereinthe washing devicce is in washing position;

FIG. 2 is another view similar to that of FIG. 1 showing the washingdevice in dry position;

FIG. 3 is still another view similar to those of FIG. I and 2 showingthe washing device in neutral position;

FIG. 4 is a partial longitudinal sectional view of FIGS. 1 to 3 fromwhich several of the parts shown in the plane of the section of FIGS. 1to 3 have beem omitted in the interest of clarity; and

FIG. 5 is a view of a detail of FIG. 4 as seen from the right-hand sidethereof.

Referring now first to FIGS. 1 to 3 and particularly to FIG. 4, there isshown therein a washing roller 2 which is traversibly mounted by twoneedle bearings 3 in a rocking frame 1. A cam 5 is secured on a shaft 4of the washing roller 2 and runs against a roller 6 which is rotatablymounted on the rocking frame I. A respective rubber raceway 7 is locatedon the shaft 4 at each side of the washing roller 2. Both rubberraceways 7, in the operating position of the washing device of theinvention as shown in FIG. 4, for example, are in frictional engagementwith respective opposing Schmitz rings or cylinder bearers 8 of ablanket cylinder 9 of an offset printing machine. As in generally known,Schmitz rings are located, for example, at the axial ends of the blanketcylinder. Depending upon the compressive load, they are formed of castiron or hardened steel. For further details regarding the constructionand installation of Schmitz rings or cylinder bearers and the operationthereof, reference can be made, for example, to U.S. Pat. No. 3,049,996of R. H. Downie.

The diameter of the rubber raceways 7 is about 1 mm. greater than thatof the soft covering I0 of the washing roller 2.

A doctor roller 14 is mounted by means of ball bearings 15 in therocking frame 1 parallel to the washing roller 2. The ball bearings 15are located in guiding grooves I6 and are displaceable in directiontoward the washing roller 2. The compressive force between a firm orhard jacket 18 of the doctor roller 14 and the soft cover 10 of thewashing roller 2 is adjustable through the displaceable ball bearings 15and the shaft IS with the aid of non-illustrated adjusting or setscrews. Another roller, namely a distributor roller 40, is located abovethe doctor roller 14. The distributor roller 40, as viewed in rotarydirection of the washing roller 2, is located behind the doctor roller14, and has a firm or hard jacket 51, similarly. The distributor roller40 is journalled in ball bearings 41 which are mounted so as to bedisplaceable in guiding grooves by non-illustrated adjusting or setscrews. By displacing the ball bearings 41, the firm or hard jacket 51of the distributor roller 40 is compressible with varying strengthagainst the soft cover 10 of the washing roller 2.

A collecting vessel 19 screens all three aforedescribed rollers 2, I4and 40 so that stripped-off ink or flung-off wash solution is collectedtherein. At the deepest location of the collected vessel 19, it isprovided with a discharge tube through which the washed-off ink togetherwith used wash solution can flow off into a larger container. Within thecollecting vessel 19, there is located a doctor blade 21 which is formedof a leaf spring 23 and a rubber blade or scraper 24. The leaf spring 23is firmly secured to the inner wall surface of the collecting vessel 19.The rubber scraper or blade 24 abuts the hard or firm jacket I8 of thedoctor roller 14 under light pressure. The jacket 18 may be covered witha hard material such as the material known by the trade name Rilsan orcan, alternatively have a copper surface layer.

Above the distributor roller 40, a drip tube 26 extends parallel to andalong the entire length of the washing roller 2. The drip tube 26 issuitably fastened to the frame 33 of the offset printing press, as bymachine screws as shown at the top of FIG. 4. The underside of the driptube 26 is provided with a plurality of drip nozzles 27 which aredisposed in a row, spaced for example 50 mm apart. The drip nozzles 27may be unscrewed from the drip tube 26, and contain a filter insert 28of felt or any other suitable permeable material. The permeability ofthe filter insert 28 determines the flow-through rate of the washsolution present in the drip tube 26. The wash solution 29 is suppliedfrom a non-illustrated container to the drip tube 26 through a feed tube30.

The nozzle openings 31 of the drip nozzles 27 are closable by seals 45.Each of the seals 45 is vulcanized to the free end of a series of leafsprings 46. Rubber is preferably used as material for the seals 45,although any other suitable material can be used therefor.

The leaf springs 46 are fastened to the rear side of a control orshifter rod 47. They are secured in such a position that the shifter rod47 can revolve to a relatively great extent without causing too great acompressive force to be applied to the seals 45 as well as withoutcausing too great a horizontal displacement of the seals with respect tothe nozzle openings 31. At both ends of the shifter rod 47, there islocated a control shaft 49, being firmly secured threadedly to theshifter rod 47. The shifter rod 47 is revolvable or rockable about therotary axis of the control shaft 49. Directly at the inner surface ofboth frame walls 33, a rocking cam 35 is provided on the control shaft49, and controls an adjusting member 34 through a cam follower roller43. The ad justing member 34 is in the form of a bell crank and carries,at one lever end thereof, the aforedescribed cam roller 43, and at theother lever end thereof, the adjusting or set screw 37, which has an endabutting a stop 42 of the rocking frame I.

The adjusting member 34 is pivotally mounted by a bearing pin 44 in theframe wall 33. The rocking frame 1 is similarly pivotally supported onboth sides rotatably on a bearing pin 32 in the frame 33 of the offsetprinting press. By rocking the adjusting member 34, the rocking frame 1can be reciprocably swung about the bearing pin 32 through a given angleof rotation so that the soft cover 10 of the washing roller 2 comes intoengagement with the rubber cloth of the blanket cylinder 9 or is againdisengaged therefrom.

At the operators side of the offset printing press, a control lever 48is secured at a free end of the control shaft 49 which extends through acasing 53. The control lever 48 is adjustable to three control positionswhich are indexted by a drop-in pin 55. In FIG. 5, the control lever 48is shown in lateral view, coordinated 4 with a scale 50 marked with thepositions Washing," "Drying" and Off."

The operation of the aforedescribed washing device is as follows:

The blanket cylinder 9 is brought into non-printing position for thepurpose of washing the same. Then the control lever 48 is swung into thecontrol position Washing." The adjustment to this setting causes theseals 45 to be swung downwardly away from the nozzle openings 31 asshown in FIG. I. Simultaneously, through the rocking cam 35, the camroller follower 43, the adjusting member 34 and the set screw 37. therocker frame I, is rocked counter-clockwise. as viewed in FIG. I, untilthe soft cover 10 of the washing roller 2 is pressed against the surfaceof the blanket cylinder 9. While wash solution then drips onto thedistributor roller from the nozzle openings 31, the blanket cylinder 9sets the washing roller 2, the doctor roller 14 and the distributorroller 40 into rotation by mutual frictional contact. The dripping washsolution 29 is transported by the distributor roller 40 in clockwisedirection as viewed in FIG. 1, for example, into the gap or nip betweenthe washing roller 2 and the distributor roller 40, a uniformdistribution of the existing wash solution being effected over theentire breadth of the soft cover 10 of the washing roller 2. The inkremoved from the blanket cylinder 9, based upon the ink-divisionprinciple is taken over to the extent of about 50 percent thereof by thedoctor roller I4 and is stripped off the latter by the rubber doctorblade 24.

If the rubber cloth covering of the blanket cylinder I is deemed by theoperator to be adequately clean, the lever 48 is then swung to theposition Drying wherein, as shown in FIG. 2, the seals close the nozzleopenings 31, while the three rollers 2, l4 and 40 of the washing devicecontinue to rotate, however. In the position Drying," the washing deviceeffects a rapid drying of the previously wetting rubber cloth 9 of theblanket cylinder 9.

After completion of the drying operation, the control lever 48 is swunginto the position Off," wherein the nozzle openings 31 remain closed bythe seals 45, as shown in FIG. 3, while the cam roller follower 43 dropsinto a depression formed in the rocker cam 35 so that, as a result ofits own weight, the entire rocker frame 1 rocks clockwise, as shown inFIG. 3, for example, to an extent that is permitted by the adjustingmember 34. In this position, the washing device is disposed in aswungaway rest or neutral setting.

As noted hereinbefore, the invention is not limited to the embodimentshown in the drawing. For example, the drip tube 26 can also be locatedabove the washing roller 2. Furthermore, it is possible to mount theseals 45 on other types of control members than that of the illustratedembodiment, such as, for example, on control members which displace theseals 45 in horizontal direction below the nozzles 27. Moreover, thecontrol of the washing device of the invention can also be effectedautomatically.

I Claim:

1. In an offset printing press having a blanket cylinder, a washingdevice adjustable with respect to the blanket cylinder and comprising arotary washing roller having a soft covering and being in frictionaldriving engagement with and traversible relative to the blanketcylinder, means for wetting said washing roller with wash solution, acollecting vessel underlying said washing roller, a doctor roller havinga firm surface located in continuous frictional engagement withsaidwashing roller, a doctor blade abutting said firm surface of saiddoctor roller for guiding therefrom into said collecting vessel inkwashed off the blanket cylinder with the wash solution, a distributorroller havinga firm surface engaging said soft covering of said washingroller at a location behind said doctor roller in the rotary directionof said washing roller, said distributor roller being wettable withfresh wash solution, a drip tube mounted above said distributor rollerand extending along substantially the entire length thereof, said driptube having a plurality of nozzles formed with nozzle openings, andfurther including sealing means, said nozzle openings being closable bysaid sealing means, a shifter rod revolvable about an axis that extendsparallel to said drip tube, leaf spring means secured to said shifterrod and having a free end, said sealing means being carried by said leafspring means at said free end thereof, said shifter rod being adjustableabout said axis to two successive indexing positions wherein saidsealing means closes said nozzle openings and to a third indexingposition wherein said nozzle openings are kept open.

2. Washing device according to claim 1, wherein said washing roller,said doctor roller and said distributor roller are mounted in a rockingframe, and including a respective control cam mounted at each end ofsaid shifter rod, and control means actuable by the control cams forrocking said roller about a given angle.

3. In an offset printing press having a blanket cylinder, a washingdevice adjustable with respect to the blanket cylinder and comprising arotary washing roller having a soft covering and being in frictionalengagement with the blanket cylinder for driving by the blanket cylinderand being traversible relative to the blanket cylinder, means forwetting said washing roller with wash solution, a collecting vesselunderlying said washing roller, a doctor roller having a firm surfacelocated in continuous frictional engagement with said washing roller fordriving by said washing roller, a doctor blade abutting said firmsurface of said doctor roller for guiding therefrom into said collectingvessel ink washed off the blanket cylinder with the wash solution, and adistributor roller having a firm surface in frictional engagement withsaid soft covering of said washing roller at a location behind saiddoctor roller in the rotary direction of said washing roller for drivingby said washing roller, said distributor roller being wettable withfresh wash solution, a drip tube mounted above said distributor rollerand extending along substantially the entire length thereof, said driptube having a plurality of nozzles formed with nozzle openings, andfurther including sealing means, said nozzle openings being closable bysaid sealing means.

4. ln an offset printing press having a blanket cylinder, a washingdevice adjustable with respect to the blanket cylinder and comprising arotary washing roller having a soft covering and being in frictionalengage ment with the blanket cylinder for driving by the blanketcylinder and being traversible relative to the blanket cylinder, meansfor wetting said washing roller with wash solution, a collecting vesselunderlying said washing roller, a doctor roller having a firm surfacelocated in continuous frictional engagement with said washing roller fordriving by said washing roller, a doctor blade abutting said firmsurface of said doctor roller for guiding therefrom into said collectingvessel ink washed off the blanket cylinder with the wash solution, and adistributor roller having a firm surface in frictional engagement withsaid soft covering of said washing roller at a location behind saiddoctor roller in the rotary direction of said washing roller for drivingby said washing roller said distributor roller being wettable with freshwash solution, said wetting means comprises means for dripping the washsolution by gravity onto the washing roller and said dripping meansincludes a material of predetermined permeability arranged for flowtherethrough of the wash solution whereby the rate of the dripping ofthe wash solution is determined by the permeability of the permeablematerial.

5. In an offset printing press having a blanket cylinder, a washingdevice adjustable with respect to the blanket cylinder and comprising arotary washing roller having a soft covering and being in frictionalengagement with the blanket cylinder for driving by the blanket cylinderand being tranversible relative to the blanket cylinder, means forwetting said washing roller with wash solution, a collecting vesselunderlying said washing roller, a doctor roller having a firm surfacelocated in continuous frictional engagement with said washing roller fordriving by said washing roller, a doctor blade abutting said firmsurface of said doctor roller for guid ing therefrom into saidcollecting vessel ink washed off the blanket cylinder with the washsolution, and a dis tributor roller having a firm surface in frictionalengagement with said soft covering of said washing roller at a locationbehind said doctor roller in the rotary direction of said washing rollerfor driving by said washing roller, said distributor roller beingwettable with fresh wash solution, a drip tube mounted above saiddistributor roller and extending along substantially the entire lengththereof, said drip tube having a plurality of nozzles formed with nozzleopenings, and further including sealing means, said nozzle openingsbeing closeable by said sealing means and said wetting means comprisesmeans for dripping the wash solution by gravity onto the distributorroller, and said dripping means includes a material of predeterminedpermeability arranged for flow therethrough of the wash solution wherebythe rate of the dripping of the wash solution is determined by thepermeability of the permeable material.

6. ln an offset printing press having a blanket cylinder, a washingdevice adjustable with respect to the blanket cylinder and comprising arotary washing roller having a soft covering and being in frictionalengage ment with the blanket cylinder for driving by the blanketcylinder in the same surface direction at point of contact and beingtraversible relative to the blanket cylinder, means for wetting saidwashing roller with wash solution, a collecting vessel underlying saidrollers, a doctor roller having a hard surface located in continuousfrictional engagement with said washing roller for driving by saidwashing roller, in the same surface direction at point of contact, adoctor blade abutting said firm surface of said doctor roller forguiding therefrom into said collecting vessel ink washed off the blanketcylinder with the wash solution, said means for wetting, comprising adistributor roller having a hard surface in frictional engagement withsaid soft covering of said washing roller at a location behind saiddoctor roller in the rotary direction of said washing roller for drivingby said washing roller, in the same surface direction at point ofcontact, said distributor roller being solution to the washing roller.

8. Washing device according to claim 6, wherein said wetting meanscomprises means for dripping the wash solution by gravity onto thedistributor roller.

9. Washing device according to claim 6, including means for supplyingthe wetting means with wash solution during the washing.

l i t i

1. In an offset printing press having a blanket cylinder, a washingdevice adjustable with respect to the blanket cylinder and comprising arotary washing roller having a soft covering and being in frictionaldriving engagement with and traversible relative to the blanketcylinder, means for wetting said washing roller with wash solution, acollecting vessel underlying said washing roller, a doctor roller havinga firm surface located in continuous frictional engagement with saidwashing roller, a doctor blade abutting said firm surface of said Doctorroller for guiding therefrom into said collecting vessel ink washed offthe blanket cylinder with the wash solution, a distributor roller havinga firm surface engaging said soft covering of said washing roller at alocation behind said doctor roller in the rotary direction of saidwashing roller, said distributor roller being wettable with fresh washsolution, a drip tube mounted above said distributor roller andextending along substantially the entire length thereof, said drip tubehaving a plurality of nozzles formed with nozzle openings, and furtherincluding sealing means, said nozzle openings being closable by saidsealing means, a shifter rod revolvable about an axis that extendsparallel to said drip tube, leaf spring means secured to said shifterrod and having a free end, said sealing means being carried by said leafspring means at said free end thereof, said shifter rod being adjustableabout said axis to two successive indexing positions wherein saidsealing means closes said nozzle openings and to a third indexingposition wherein said nozzle openings are kept open.
 2. Washing deviceaccording to claim 1, wherein said washing roller, said doctor rollerand said distributor roller are mounted in a rocking frame, andincluding a respective control cam mounted at each end of said shifterrod, and control means actuable by the control cams for rocking saidroller about a given angle.
 3. In an offset printing press having ablanket cylinder, a washing device adjustable with respect to theblanket cylinder and comprising a rotary washing roller having a softcovering and being in frictional engagement with the blanket cylinderfor driving by the blanket cylinder and being traversible relative tothe blanket cylinder, means for wetting said washing roller with washsolution, a collecting vessel underlying said washing roller, a doctorroller having a firm surface located in continuous frictional engagementwith said washing roller for driving by said washing roller, a doctorblade abutting said firm surface of said doctor roller for guidingtherefrom into said collecting vessel ink washed off the blanketcylinder with the wash solution, and a distributor roller having a firmsurface in frictional engagement with said soft covering of said washingroller at a location behind said doctor roller in the rotary directionof said washing roller for driving by said washing roller, saiddistributor roller being wettable with fresh wash solution, a drip tubemounted above said distributor roller and extending along substantiallythe entire length thereof, said drip tube having a plurality of nozzlesformed with nozzle openings, and further including sealing means, saidnozzle openings being closable by said sealing means.
 4. In an offsetprinting press having a blanket cylinder, a washing device adjustablewith respect to the blanket cylinder and comprising a rotary washingroller having a soft covering and being in frictional engagement withthe blanket cylinder for driving by the blanket cylinder and beingtraversible relative to the blanket cylinder, means for wetting saidwashing roller with wash solution, a collecting vessel underlying saidwashing roller, a doctor roller having a firm surface located incontinuous frictional engagement with said washing roller for driving bysaid washing roller, a doctor blade abutting said firm surface of saiddoctor roller for guiding therefrom into said collecting vessel inkwashed off the blanket cylinder with the wash solution, and adistributor roller having a firm surface in frictional engagement withsaid soft covering of said washing roller at a location behind saiddoctor roller in the rotary direction of said washing roller for drivingby said washing roller, said distributor roller being wettable withfresh wash solution, said wetting means comprises means for dripping thewash solution by gravity onto the washing roller and said dripping meansincludes a material of predetermined permeability arranged for flowtherEthrough of the wash solution whereby the rate of the dripping ofthe wash solution is determined by the permeability of the permeablematerial.
 5. In an offset printing press having a blanket cylinder, awashing device adjustable with respect to the blanket cylinder andcomprising a rotary washing roller having a soft covering and being infrictional engagement with the blanket cylinder for driving by theblanket cylinder and being tranversible relative to the blanketcylinder, means for wetting said washing roller with wash solution, acollecting vessel underlying said washing roller, a doctor roller havinga firm surface located in continuous frictional engagement with saidwashing roller for driving by said washing roller, a doctor bladeabutting said firm surface of said doctor roller for guiding therefrominto said collecting vessel ink washed off the blanket cylinder with thewash solution, and a distributor roller having a firm surface infrictional engagement with said soft covering of said washing roller ata location behind said doctor roller in the rotary direction of saidwashing roller for driving by said washing roller, said distributorroller being wettable with fresh wash solution, a drip tube mountedabove said distributor roller and extending along substantially theentire length thereof, said drip tube having a plurality of nozzlesformed with nozzle openings, and further including sealing means, saidnozzle openings being closeable by said sealing means and said wettingmeans comprises means for dripping the wash solution by gravity onto thedistributor roller, and said dripping means includes a material ofpredetermined permeability arranged for flow therethrough of the washsolution whereby the rate of the dripping of the wash solution isdetermined by the permeability of the permeable material.
 6. In anoffset printing press having a blanket cylinder, a washing deviceadjustable with respect to the blanket cylinder and comprising a rotarywashing roller having a soft covering and being in frictional engagementwith the blanket cylinder for driving by the blanket cylinder in thesame surface direction at point of contact and being traversiblerelative to the blanket cylinder, means for wetting said washing rollerwith wash solution, a collecting vessel underlying said rollers, adoctor roller having a hard surface located in continuous frictionalengagement with said washing roller for driving by said washing roller,in the same surface direction at point of contact, a doctor bladeabutting said firm surface of said doctor roller for guiding therefrominto said collecting vessel ink washed off the blanket cylinder with thewash solution, said means for wetting, comprising a distributor rollerhaving a hard surface in frictional engagement with said soft coveringof said washing roller at a location behind said doctor roller in therotary direction of said washing roller for driving by said washingroller, in the same surface direction at point of contact, saiddistributor roller being wettable with fresh wash solution, said doctorroller acting to remove dirty material from said washing roller beforeclean washing solution is deposited on said washing roller by saiddistributor roller and means to dry said blanket cylinder includingmeans to remove the supply of wash solution.
 7. Washing device accordingto claim 6, wherein said wetting means comprises means for supplying thewash solution to the washing roller.
 8. Washing device according toclaim 6, wherein said wetting means comprises means for dripping thewash solution by gravity onto the distributor roller.
 9. Washing deviceaccording to claim 6, including means for supplying the wetting meanswith wash solution during the washing.